Compliant Remote Center Motion Mechanism for Minimally Invasive Surgical Robots

The Intuitive/sup TM/ telesurgery system: overview and application

Abstract: The paper briefly describes daVinci/sup TM/, a surgical telerobot designed to provide enhanced dexterity to doctors performing minimally invasive surgical procedures. The rationale for a full 7-degree-of-freedom master-slave system is presented along with a discussion of the resulting computational architecture and recent clinical applications.

The Black Falcon: a teleoperated surgical instrument for minimally invasive surgery

Abstract: This paper presents the Black Falcon, an eight degree-of-freedom teleoperator slave with a dextrous wrist for minimally invasive surgery (MIS). We show how teleoperation can address several key problems in MIS by increasing dexterity and degrees of freedom, by giving the surgeon some force feedback to feel instrument-tissue interactions and by eliminating geometric discrepancies between actual and observed tool motions. We discuss relevant design constraints, summarize the mechanism design and give data showing the quality of force reflection achieved. We demonstrate suturing along arbitrarily oriented suture lines in animal tissue, a task essentially impossible using current instruments.

Surgical Forces and Tactile Perception During Retinal Microsurgery

Abstract: Purpose: Vitreoretinal surgery involves the manipulation of delicate retinal membranes with a required surgical accuracy often on the order of tens of microns, a scale at or near the limit of human positional ability. In addition, forces imposed by the tissue on the surgical cool are exceedingly small. Here we investigate the magnitude of forces generated during retinal surgery in cadaveric porcine eyes and compare the results with the magnitude of forces discernable by retinal surgeons. This data will be used as a design guideline for robotic surgical augmentation systems currently under development Methods: The study was performed in two phases. First, retinal surgeons manipulated the retina of porcine cadaver eyes with a calibrated 1-axis force sensing retinal pick while data was simultaneously recorded. In the second phase, blindfolded subjects held the pick and were instructed to press a button whenever an “event” was felt. Events were generated by slowly tapping the end of the pick with varying force while both the magnitudes of forces applied and the responses of the subjects we recorded. The magnitudes of forces generated during retinal surgery were then compared with those that could be discerned by the subjects. Results: Roughly 75% of all forces measured during retinal microsurgery were found to be less than 7.5 mN in magnitude, however only 19.3 ± 8.1% (N=492) of events generated at this level could be felt by the subjects. Conclusions: The results of this study indicate that a majority of retinal surgery is probably performed without the surgeon being able to “feel” interactions between retinal tissue and the surgical tool. Prior studies have indicated that relying on visual feedback alone increases the length of manual manipulation tasks and reduces task accuracy. The lack of tactile sensation during retinal surgery similarly could adversely affect surgical outcome.

A parallel robot to assist vitreoretinal surgery.

Abstract: This paper describes the development and evaluation of a parallel prototype robot for vitreoretinal surgery where physiological hand tremor limits performance. The manipulator was specifically designed to meet requirements such as size, precision, and sterilization; this has six-degree-of-freedom parallel architecture and provides positioning accuracy with micrometer resolution within the eye. The manipulator is controlled by an operator with a “master manipulator” consisting of multiple joints. Results of the in vitro experiments revealed that when compared to the manual procedure, a higher stability and accuracy of tool positioning could be achieved using the prototype robot. This microsurgical system that we have developed has superior operability as compared to traditional manual procedure and has sufficient potential to be used clinically for vitreoretinal surgery.